Marshall JMP PA 2002 preset

Verified · 86/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Marshall 2002 is a 50-watt valve PA head from 1970. Four input pairs run into the four triodes of two ECC83s, each with its own volume and identical simple tone controls, mixed into a shared ECC83 gain stage and cathode follower driving Treble, Middle and Bass. An ECC83 long-tail inverter with Presence drives two fixed-bias EL34s on a silicon bridge, so it can double as a Marshall guitar head.

• Made in: UK
• Wattage: 50W
• Channels: 1
• Preamp tubes: 4× ECC83
• Power tubes: 2× EL34

Tags: british, vintage, el34, clean, breakup.

Schematic-derived preset files for 16 Fractal and Line 6 modelers: Axe-Fx II/XL/XL+, Axe-Fx III, FM3, FM9, and the full Helix family (Floor, LT, Rack, HX Stomp, HX Stomp XL, Native).

Gridleak extracts amp parameters from original circuit schematics using AI vision — component values, gain staging, tone stack topology, tube types — then generates native preset files for every supported modeler. Every extraction is scored 0–100 and the score is published.